A former trade adviser to controversial think tank the Legatum Institute held numerous unminuted meetings with senior Brexit policymakers including David Davis and Boris Johnson, according to newly released documents.

Shanker Singham, a former Washington lobbyist – who has been said to enjoy “unparalleled access” to senior government figures – left Legatum earlier this year to head up a new trade unit at the Institute of Economic Affairs.

At an event in Glasgow last week, Singham, billed by the organisers as “one of the world’s leading trade lawyers”, complained that the UK’s “lack of clarity” over Brexit was causing “confusion”.

He had repeated private meetings with the highest official in the Department for Exiting the European Union (DexEU), permanent secretary Philip Rycroft. Two were at DExEU’s Whitehall offices in March and May this year, just after Singham left Legatum.

Data compiled by openDemocracy also shows that since the Brexit vote in June 2016, Singham has had dozens of meetings with British government ministers including Boris Johnson, David Davis and Liam Fox. The meetings and events were either unminuted or information relating to them was withheld by government departments. Singham also had undeclared meetings with Brexit ministers.

The Ferret reported in June that the charity regulator had ruled that Legatum’s work on Brexit “crossed a clear line” and “failed to meet the required standards of balance and neutrality”.

Former Labour minister, Liam Byrne MP, called for more transparency from government over Singham’s contact with ministers and senior officials.

“It beggars belief that ministers and officials are spending hour after hour with Hard Brexit svengali, Shanker Singham. He may have ditched his Legatum badge but I suspect his views are as hard line as ever, and as bad for Britain as ever,” he said.

Singham has also had extensive contact with Brexit trade minister, Greg Hands. The pair met at least half a dozen times in the space of a few months at the end of 2017. “I hope we can meet frequently and monthly is a good objective,” Hands wrote to Singham in October, according to emails obtained by openDemocracy.

In December alone Singham had two meetings with Hands, two meetings with Rycroft from DExEU, and a meeting with Michael Gove and Antonia Romeo, a senior civil servant at Fox’s Department for International Trade.

After a request for comment, Singham said that “you can find information about my meetings in the transparency register.”

Singham is also closely associated with Brexit minister Steve Baker. An investigation by Buzzfeed found that Singham had multiple undeclared meetings with Baker, and former Legatum trade advisor Crawford Falconer, who now works at the Department of International Trade. These meetings were not recorded in official government transparency records.

Documents released following freedom of information requests show Singham had a one-on-one meeting with Philip Rycroft on 13 March, just days after it was announced that he would be leaving the Legatum Institute. On 10 May, Singham met with Rycroft and Eoin Parker, director of market access and budget at DExEU.

Singham, who argues that Britain needs to leave the single market and customs union to maximise opportunities outside the EU, has emerged as an influential trade voice for Brexit. His name has been cited in Parliament and his trade papers held up as evidence that Britain should leave the customs union and single market.

The recent proposal that the UK could create a ten-mile wide ‘buffer zone’ along the Irish border originated from a paper published by Singham and the Legatum Institute.

Think tank ‘crossed the line’ on Brexit, Charity Commission finds

The Charity Commission strongly criticised Legatum on Brexit. A Legatum report entitled, Brexit Inflection Point, did not present “balanced, neutral evidence and analysis” and was “not consistent” with the charity’s objectives to promote education, the regulator found. Legatum withdrew from doing work on Brexit earlier this year.

Former Charity Commission board member Andrew Purkis has said that the regulator’s ruling on Legatum also raised questions about the Singham’s new employers, the Institute of Economic Affairs. The IEA, which also has charitable status, also recently appointed Vote Leave donor Jon Moynihan to its board.

The IEA has also hired Darren Grimes as its digital manager. Grimes, who had worked for Brexit Central, is subject of an Electoral Commission investigation in relation to a £675,000 donation from Vote Leave during the Brexit referendum. A judicial review into the Electoral Commission’s handling of Vote Leave spending is due to be heard on 19 June.

The Legatum Institute announced in March 2018 that it would be ending its Brexit work following public scrutiny of the think tank’s work and its funding.

This story was co-authored by Jenna Corderoy. A version of this story was published on openDemocracy on 14 June 2018.